Control system for bathers

Abstract

A control system for bathers includes an electronic controller which controls operation of an electric heater assembly connected in a water flow path for heating water. The heater assembly includes a heater housing and electric heater element. A solid state water temperature sensor apparatus provides electrical temperature signals to the controller indicative of water temperature at separated first and second locations on or within the heater housing. The presence of water in the heater housing is detected electronically, by turning on the heater, and monitoring the temperature sensors for unusual temperature rises or other faults for a period of time thereafter. A solid state water presence sensor apparatus can also be used to determine the presence of water within the heater housing, providing electrical water presence signals to the controller indicative of the presence or absence of a body of water within the heater housing. An independent circuit apparatus is connected to the water temperature sensor apparatus and to a power relay, automatically causing high voltage power to be disconnected from the heater assembly when the water temperature exceeds a predetermined temperature. The independent circuit apparatus requiring a manual reset once the water temperature has dropped below a predetermined level to allow the high voltage power to be reconnected to the heater assembly. The system includes ground continuity detection, ground current detection and ground fault detection circuits.

What is claimed is:  
     
       1. A heating and control system for bathers, comprising: 
       an electronic controller;  
       an electric heater assembly connected in a water flow path for heating water passing therethrough, comprising a heater housing and electric heater element, the controller arranged to control the operation of the heater element;  
       water temperature sensor apparatus providing electrical temperature signals to the controller indicative of water temperature at separated first and second locations on or within said heater housing or a combination thereof;  
       water presence sensor apparatus to determine the presence or absence of water within said heater housing, and to provide electrical water presence signals to the controller indicative of the presence or absence of a body of water within the heater housing;  
       the controller responsive to signals from the water temperature sensor apparatus and the electrical water presence signals to control the heater element, said controller responsive to said electrical water presence signals indicating the absence of a body of water within the heater housing to disable operation of the heater element, and to automatically enable operation of the heater element upon subsequent receipt of water presence signals indicating the presence of a body of water within the heater housing.  
     
     
       2. A system according to claim  1  wherein said controller energizes the heater assembly only when the temperature sensed at said first location and the temperature sensed at said second temperature location are within predetermined limits. 
     
     
       3. A system according to claim  1  wherein the water presence sensor apparatus comprises a solid state sensing device. 
     
     
       4. A system according to claim  3  wherein the solid state sensing device comprises apparatus for passing an electrical sensing signal through the body of water if present within the heater housing, and a detector circuit to detect said electrical sensing signal. 
     
     
       5. A system according to claim  4 , wherein the detector circuit generates said electrical water presence signals indicative of the presence or absence of a body of water within the heater housing. 
     
     
       6. A system according to claim  1 , wherein the water presence sensor apparatus employs the electrical conductivity of a body of water within the heater housing to detect the presence or absence of the body of water therein. 
     
     
       7. A system according to claim  1 , wherein the water presence sensor apparatus is free of any moving mechanical parts. 
     
     
       8. A system according to claim  1  wherein the water presence sensor apparatus comprises the controller and said water temperature sensor apparatus, and wherein the controller collects temperature values before and after operating the heater assembly for a given time interval, and determines whether water is present as a result of the difference in the before and after temperature values. 
     
     
       9. A system according to claim  1  wherein the water temperature sensor apparatus comprise a plurality of solid state temperature probes. 
     
     
       10. A system according to claim  1 , further including a controller enclosure, and wherein the controller includes a controller circuit board within the controller enclosure, and wherein the heater assembly is attached to the controller enclosure. 
     
     
       11. A system according to claim  1 , wherein the first location is at or adjacent a water entrance of the heater assembly, and the second location is at or adjacent a water exit of the heater assembly. 
     
     
       12. A system according to claim  1  wherein said controller energizes the heater assembly only when the temperature sensed at said first location and the temperature sensed at said second temperature location are within predetermined limits. 
     
     
       13. A system according to claim  1  wherein the controller deactivates operation of said heater assembly if said water temperature sensor apparatus detects a temperature rate of rise at said first location or at said second location that exceeds a certain specified value. 
     
     
       14. A system according to claim  1  wherein the controller compares the respective temperatures detected at said first and second locations and uses the lower of said temperatures to control the activation and deactivation of the heater. 
     
     
       15. A system according to claim  1 , further comprising a pump for circulating water through the heater assembly, the pump controlled by the controller. 
     
     
       16. A system according to claim  15  wherein the pump has a water input and a water output, and wherein the water output of said pump is directed into said heater assembly. 
     
     
       17. A system according to claim  15  wherein the water input of said pump is through the heater assembly. 
     
     
       18. A system according to claim  3  wherein the controller deactivates operation of said heater assembly if said water temperature sensor apparatus detects a temperature rate of rise at said first location or at said second location that exceeds a certain specified value. 
     
     
       19. A system according to claim  3  wherein the controller compares the respective temperatures detected at said first and second locations and uses the lower of said temperatures to control the activation and deactivation of the heater. 
     
     
       20. A heating and control system for bathers for heating water, comprising: 
       a control circuit board assembly comprising at least one power switching device;  
       a high voltage power supply connected to said control circuit board assembly;  
       a control panel for inputting user preferences;  
       a heater assembly comprising a heater housing element connected to said control circuit board assembly;  
       a first water pump connected to said control circuit board assembly;  
       a microprocessor coupled to said control panel and to said control circuit board assembly, said microprocessor adapted to process signals from a plurality of devices providing water parameter information and to energize said heater according to user preferences;  
       a water presence sensor apparatus for detecting the presence of water in said heater housing element;  
       a water temperature sensor apparatus for providing electrical temperature signals to the controller indicative of water temperature at separated first and second. locations on or within said heater housing or a combination thereof; and  
       independent circuit apparatus connected to said water temperature sensor apparatus and to said at least one power switching device, said independent circuit apparatus for automatically causing the high voltage power to be disconnected from the heater assembly when the water temperature exceeds a predetermined temperature, said independent circuit apparatus requiring a manual reset once the water temperature has dropped below a predetermined level to allow the high voltage power to be reconnected to the heater assembly.  
     
     
       21. A system according to claim  20 , wherein the temperature sensor apparatus includes a first temperature sensor for sensing a first water temperature at a first location and a second temperature sensor for sensing a second water temperature sensor at a second location, wherein said independent circuit apparatus includes a first separate circuit responsive to the first temperature sensor for disconnecting the heater when the first temperature exceeds said predetermined temperature, and a second separate circuit responsive to the second temperature sensor for disconnecting the heater when the second temperature exceeds said predetermined temperature. 
     
     
       22. A system according to claim  20  with a second water pump or an air blower connected to said control circuit board assembly, said first pump activated whenever said second pump or air blower is activated. 
     
     
       23. A system according to claim  22  wherein said second pump or said air blower is deactivated whenever said water temperature exceeds a certain amount. 
     
     
       24. A system according to claim  20 , wherein the water presence sensor apparatus is a solid state system free of any moving mechanical parts. 
     
     
       25. A heating and control system for bathers, comprising: 
       a control circuit board assembly comprising at least one power switching device;  
       a high voltage power supply connected to control circuit board assembly;  
       a heater assembly including a heater housing and heater element, said heater element connected to said control circuit board assembly;  
       a microprocessor adapted to process signals from a plurality of input devices providing information regarding water parameters and to energize said heater according to user preference;  
       a water temperature sensor apparatus for providing electrical temperature signals to the microprocessor indicative of water temperature at separated first and second locations on or within said heater housing or a combination thereof;  
       independent circuit apparatus separate from said microprocessor and connected to the water temperature sensor apparatus and connected to at least one power switching device in the control circuit board assembly;  
       said independent circuit apparatus automatically causing the high power supply to be disconnected from the heater assembly when the temperature exceeds a predetermined temperature, said circuit apparatus requiring a manual reset once the temperature has dropped below a predetermined level.  
     
     
       26. A system according to claim  25 , wherein the temperature sensor apparatus include a first temperature sensor for sensing a first water temperature at a first location and a second temperature sensor for sensing a second water temperature sensor at a second location, and wherein the independent circuit apparatus including a first separate circuit responsive to the first temperature sensor for disconnecting the heater when the first temperature exceeds said predetermined temperature, and a second separate circuit responsive to the second temperature sensor for disconnecting the heater when the second temperature exceeds said predetermined temperature. 
     
     
       27. A system according to claim  25  including a control panel mounted within user access on the spa, said control panel containing a user-activated device to activate a reset of said independent circuit apparatus. 
     
     
       28. A spa including a heating and control system for bathers, comprising: 
       an outdoor vessel for holding a body of water, the vessel intended to maintain the body of water in a substantially filled condition;  
       a control circuit board assembly;  
       a high voltage power supply connected to the control circuit board assembly;  
       a heater assembly physically connected to the control circuit board assembly;  
       water presence sensor apparatus to determine the presence of water within the heater assembly and provide water presence signals indicative of the presence or absence of a body of water within the heater assembly;  
       a pump for recirculating water through said heater assembly and said vessel;  
       water temperature sensor apparatus providing electrical temperature signals indicative of water temperature at separated first and second locations on or within said heater assembly;  
       an electronic controller comprising said control circuit board assembly for selectively activating and deactivating said pump at selected time intervals, said controller responsive to said temperature signals and said water presence signal to manage water parameters, said controller configured to disable operation of said heater in the absence of water within the heater assembly, and to automatically enable operation of the heater element upon subsequent receipt of water presence signals indicating the presence of a body of water within the heater housing.  
     
     
       29. A system according to claim  28  whereby said time intervals are determined by calculating the rate of heat loss of the spa. 
     
     
       30. A system according to claim  28  whereby said time intervals are varied to minimize the number of iterations of activation and deactivation of the pump. 
     
     
       31. A system according to claim  28  whereby the pump is activated for a short interval of time, and then deactivated if the temperature of the water is within a specified range of a selected temperature. 
     
     
       32. A system according to claim  28  wherein the electronic controller comprises a microprocessor connected to the control circuit board assembly. 
     
     
       33. A system according to claim  28  wherein the water presence sensor apparatus comprises the controller and said water temperature sensor apparatus, and wherein the controller collects temperature values before and after operating the heater assembly for a given time interval, and determines whether water is present as a result of the difference in the before and after temperature values. 
     
     
       34. A system according to claim  28  wherein said controller energizes the heater assembly only when the temperature sensed at said first location and the temperature sensed at said second temperature location are within predetermined limits. 
     
     
       35. A system according to claim  28  wherein the controller deactivates operation of said heater assembly if said water temperature sensor apparatus detects a temperature rate of rise at said first location or at said second location that exceeds a certain specified value. 
     
     
       36. A system according to claim  28  wherein the controller compares the respective temperatures detected at said first and second locations and uses the lower of said temperatures to control the activation and deactivation of the heater. 
     
     
       37. A method for detecting the presence of water in a system including a heater element, a heater housing, and a microcomputer, the microcomputer controlling the heater, at least one temperature sensor in close proximity to the heater element, the temperature sensor feeding temperature data to the microcomputer, the method comprising: 
       collecting and storing a first temperature measurement value;  
       activating the heater element for a predetermined time interval;  
       deactivating the heater element for a selected time interval;  
       collecting and storing a second temperature measurement value;  
       calculating the difference between the first temperature measurement value and the second temperature measurement value;  
       comparing the resulting difference to a predetermined value to establish the presence or absence of water adjacent the heater element.  
     
     
       38. A method according to claim  37 , wherein said at least one temperature sensor includes first and second temperature transducers, and said first and second temperature values are respectively collected from said first and second temperature transducers. 
     
     
       39. A method according to claim  38  wherein said first and second temperature transducers are in thermal contact with said heater housing. 
     
     
       40. A method according to claim  37 , further characterized in that the at least one temperature sensor is in thermal contact with the heater housing. 
     
     
       41. A heating and control system for bathers, comprising: 
       an electronic controller;  
       an electric heater assembly connected in a water flow path for heating water passing therethrough, comprising a heater housing and electric heater element, the controller arranged to control the operation of the heater element;  
       water temperature sensor apparatus providing electrical temperature signals to the controller indicative of water temperature at separated first and second locations on or within said heater housing or a combination thereof;  
       and  
       a water presence sensor apparatus to determine the presence or absence of water within said heater housing, the water presence sensor apparatus comprising the controller, and wherein the controller collects temperature values before and after operating the heater assembly for a given time interval, and determines whether water is present as a result of the difference in the before and after temperature values.